Equate what is inside cosine with
, base period and solve for x,



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Answer:
Part c) 
Part d)
or 
Step-by-step explanation:
Part c) Find the volume of the inverted rectangular pyramid
The volume of the rectangular pyramid is equal to

where
B is the area of the rectangular base
h is the height of pyramid
<em>Find the area of the base B</em>


substitute


Part d) Find the maximum volume of tea in the tea cup
we know that
The volume of cylinder (tea cup) is equal to

we have

substitute

-----> exact value
<em>Find the approximate value</em>
assume


Answer: 
Step-by-step explanation:










Answer:
x = 32
Step-by-step explanation:
x + 10 = 42, then you subtract 10 from both sides to get 32